After trying to trap the yellow jackets and only getting a few dozen it was obvious that traps would not do the trick so I tried printing some wasp/yellow jacket/ bee proof feeders. They all leak 5 of them. Now the yellow jackets are swarming all over the last one still hanging so they are obviously getting fed by it.

Time for the next step. Make the feeders we already have only let the hummingbirds get the food. After reading a bit I came up with the simple solution of making a grommet for the hole the birds get the food from with a opening that will let hummingbirds feed but not anything else.

Out came the calipers. Opened up Inventor and in less than an hour it's ready to print.

You can see the wall was too thin to print in the middle so it leaves a hole through the side but that doesn't matter since that is inside and doesn't allow access to the food and it can't even be seen once installed.

Printed it in TPU so it's soft for the birds and flexible as a grommet should be. Even printed it in red. They're small enough that 36 can be printed in 1 hour. The feeders have 10 holes each so some spares in case some get lost somehow. Oh yeah, 72 will fit easily on bed & is a 2 hour print.

How I did it with 7 feeders is:

1. Print the grommets
2. Trim the strings and push the punch (ice pick like thing about 3-4mm thick) through each one.
3. Press all into the feeders holes.
4. Press each one in good with thumbnail so they're all seated well.
5. Hit each ones hole with a butane torch for about 1 second to eliminate any strings/rough edges. It also makes the opening open to the elliptical shape they were designed with.
6. Fill the feeders and watch everything go away unsatisfied but the hummingbirds.

If you get really small ants then you need an ant moat. I like this one I remixed from the one by Intrglctcrevfnk:
https://www.thingiverse.com/thing:2566167